Clean the mason jars and set them aside so they are ready to go.
Add the bell peppers and scotch bonnets to a food processor. Cover and pulse until minced. (You may need to do this in batches depending on the size of your processor.)
Transfer the minced peppers and any liquid in the processor bowl to a large pot along with the sugar and vinegar. Place over medium heat and bring to a boil.
Add the liquid pectin and keep the mixture at a rolling boil for about 15 minutes, stirring occasionally. (Stay close to the pot to ensure it doesn't boil over.) Skim off any foam that forms on top.
When an instant-read thermometer reads 217 to 222 degrees F, remove the jelly from the heat.
Pour the jelly into the prepared mason jars, leaving a little bit of room at the top. Put on the lids and set rest for 12-24 hours for the jelly to set up. (The heat from the jelly should create a full seal on the jars.)
Notes
This recipe makes about seven 8-ounce jars.
Once the jars are sealed, they can be kept at room temperature for up to 1 year. Once a jar is opened, store it in the fridge for up to 3 weeks.
For hotter jelly, leave in as many scotch bonnet seeds as you like. The more you add, the hotter the jelly will be.
Habanero peppers can be substituted for scotch bonnet peppers, depending on what's available at your grocery store.